1. Field of the Invention
2. Brief Description of the Prior Art
The present invention relates to a piston pump with reduced clearance volume, so that the efficiency of the piston pump can be increased. The piston pump of the invention is used particularly in brake systems of motor vehicles with active pressure buildup.
From the prior art, various embodiments of piston pumps are known. Piston pumps that are used particularly in brake systems of vehicles must have the lowest possible weight and the most compact possible construction. Piston pumps are known that aspirate a fluid through the piston into a pressure chamber and that increase the pressure of the aspirated fluid in the pressure chamber. The pressure chamber is disposed in a cylinder that has an inner bore of constant diameter. An outlet from the pressure chamber is provided in the base of the cylinder. Besides a restoring element for the piston, the pressure chamber also contains a check valve for closing or opening an inlet opening provided in the piston. In principle, such piston pumps have proven themselves, but it would be desirable to further increase the efficiency of such piston pumps and in particular to reduce the clearance volume.